Ecosystem Carbon Storage In Zoige Alpine Marsh Of Southwest China

Accurate investigating of spatial distributions and environmental controls of carbonstorage in Zoige marsh ecosystems is important for predicting the consequences of globalchange and designing sustainable rangeland management.In the current study, we collected datasets about vegetation quadrats, abovegroundbiomass and underground biomass, physicochemical properties of the soil and the waterelevation from32sites of the Zoige marsh during July and August2011-2012when thebiomass production approximately reached a pleatu. We collected the TM remote sensingimage data, the average annual precipitation and mean annual temperature data from1971to2000at the Zoige alpine swamp. Using the class II regression, analysis of variance, CCA, RDAanalysis, correlation analysis and other classic statistical methods and Kriging geostatisticalmethods, we examined the relationship between species richness and aboveground biomass.The biomass allocation in Zoige marsh and spatial distributions were estimated. Potentialenvironmental controls for the carbon storage in Zoige marsh were analyzed. The main resultsare as follows:(1)There are147species in Zoige marsh, belonging to39families and98genera.Environmental factors are important determinants of the distribution of native plant species inZoige marsh. We found no relationship between species richness and aboveground biomass,which was possibly due to their no variations along the environmental factor gradients.(2)The average aboveground biomass (AGB), belowground biomass (BGB) and totalbiomass (TB) for Zoige alpine marsh were367.05,3680.36and4048.01g·m-2, respectively.The micro-topography (hummock-hollow topography) can lead to the spatial variations ofbiomass in local scale. Biomass descends from north to south and increases from the center tothe edge of the swamp. Lake depression has a higher biomass than river gully. There were positively allometric relationship (p<0.05) between aboveground biomass components andbelowground biomass especially for sites with a low level of soil nutrients.(3)The average0-30cm、0-50cm、0-100cm、0-200cm soil organic carbon density for Zoigealpine marsh were19.48(9.72-44.65)、32.54(17.58-42.52)、77.97(44.06-127.77) and140.67(76.89-275.75), respectively. Zoige alpine swamp with a total area of2754.52km2mainlydistributed in Zoige County, Hongyuan County, Aba County and Maqu County. The total Cstock in Zoige alpine swamp (0-200cm) was392.72Tg,which is lower than the past research ofnational scale estimation. The main uncertainty factors in carbon stock estimation include thedifferences in data sources, samples and estimation methods.(4)Our results indicate that there are similarities in vertical distribution of the roots，R/S(BGB/AGB) ratio and soil organic carbon density between high altitude marsh ecosystems andhigh latitudes peatlands partly were due to the similarities of cold temperature and lowprecipitation.